Zohar Atkins is bothered by the goblet that Yosef has hidden in Binyamin’s sack:
The text makes a big deal about Yosef’s ניחוש, divination, magic tricks, with this goblet. And while we don’t see it explicitly used in the Torah, the aggadah points out hints:
The Tanchuma adds that the divination cup is נכרי, foreign, to the בני שראל way of thinking. And this is what Yosef frames them with. Why would they steal this goblet specifically? The Tanchuma suggests that Binyamin would have wanted to find his brother:
The בית הלוי suggests that the very fact that it was a magic cup made it valuable:
I think the most logical reason why they would have stolen it is the reason suggested by the שפתי חכמים:
This is implied by the בית הלוי as well. If they were spies, then they would steal the magic cup to stop Yosef from being able to track them down. It reminds us of the time Yosef’s mother stole her father’s magic statues:
Now, Rashi says she stole them to keep her father away from idol worship, but Rashbam notes that Lavan clearly believed in magic, and in divination:
So Rashbam proposes that Rachel also believed in the power of the magic statues, and that is why she stole them:
Asher Wassertheil notes the connection to our story, and the fact that the brothers must have known about it:
Any way you understand it, the accusation only makes sense if the brothers think that the divination cup is real, that it has value and power. But they don’t. That’s a נכרי mindset.
Atkins proposes that this is the point Yosef is trying to make to his brothers: you know, and I know, and I know you know, and you know I know, that there is no magic in the cup.
The brothers object that they know this—the symbol is not the thing, and taking away the symbol doesn’t affect the underlying reality. Yosef says, “Aha! And what about a certain multi-colored coat, 22 years ago?”
Yosef is reminding them, “You were jealous of a coat and a couple of dreams, and you thought that if you destroyed those—(בראשית לז:כ) וְנִרְאֶה מַה יִּהְיו חֲלֹמֹתָיו—you would solve the problem. But they were just symbols of my potential as a human being. Kidnapping me was just as pointless as stealing by goblet would have been. If you want to deal with my potential greatness, you need to become greater yourselves.” It’s not so much that stealing the coat was like stealing the goblet, but that getting rid of Yosef was like getting rid of the goblet. They wouldn’t solve their problem, wouldn’t make Yaakov appreciate them more, by killing Yosef.
And effectively that is what Yehudah does in the next parsha, becoming the leader who will pull the brothers back together into a nation.